Accessing external storage data after OS crash

Nextcloud version (eg, 18.0.2): 18.0.2
Operating system and version (eg, Ubuntu 20.04): DietPi Raspberry Pi 4
Apache or nginx version (eg, Apache 2.4.25): Ngnx
PHP version (eg, 7.1): 7.2

The issue you are facing:
I had an OS crash and lost everything. I stored all data directly to an external HD. My issue is I can see all the files and directories on my Windows PC and on my newly flashed Pi, however, I can’t open, or access any of them. I keep getting unsupported format on windows and on Linux I am getting

jpeg file starts with 0x48 0x42

I really just want to access my data again. Any ideas?

Is this the first time you’ve seen this error? (Y/N):

Steps to replicate it:

  1. Format OS where NC is installed.

The output of your Nextcloud log in Admin > Logging:
NA

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):
NA

The output of your Apache/nginx/system log in /var/log/____:
NA